Revamping computer

Hey all,

My system is starting to wear down and I am looking to update some of my computer parts. Computer is mainly for gaming.

Currently I have:

EVGA 132-CK-NF78-A1 LGA 775 NVIDIA nForce 780i SLI ATX Intel Motherboard

BFG Tech BFGE88512GTSE GeForce 8800GTS (G92) 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card

PC Power and Cooling S75QB 750W ATX12V / EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply compatible with core i7

CORSAIR XMS2 DHX 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model TWIN2X4096-6400C4DHX

Western Digital Caviar Blue WD6400AAKS 640GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive

SAMSUNG 20X DVD±R DVD Burner with LightScribe Black SATA Model SH-S203N LightScribe Support - OEM

XIGMATEK HDT-S1283 120mm Rifle CPU Cooler


I was looking to replace the motherboard, cpu, memory and gpu with:

Motherboard - ASUS M4A89GTD PRO/USB3 AM3 AMD 890GX
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

CPU - AMD Phenom II X4 955 Black Edition Deneb 3.2GHz
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Ram - G.SKILL Ripjaws Series 4GB (2 x 2GB)
http://www.newegg.com/Product/ProductList.aspx?Submit=E...

GPU - XFX HD-585X-ZNFC Radeon HD 5850
http://www.newegg.com/Product/Product.aspx?Item=N82E168...


The advice I'm looking for is if there might be any compatibility issues with my HDD, PSU and Optical drive. Also if anyone has any other suggestions for the 4 components I'd be happy to hear them.